Funny discrepancy in System clock & file creation date on R4600 IP22

[Serge Gagne <sgagne@flashsolutions.qc.ca>]

I have just install for the first time debian on a SGI Indy R4600 100Mhz
160Mo.  The installation went fine. I downloaded libIDL-0.6.8.tar.gz in
/usr/src then started tar zxvf to find out that the file creation date
tar produced was sometime in 1997!  The date command report the current
date correctly! I'm unable to ./configure libIDL cause my system
obviously in not sane timewise ;-(

If somebody have a fix or an explanation i'll be please to hear it...